Fix buffer overflow when flushing Redis cache tags with many keys (#57562)

Author: faisuc

src/Illuminate/Cache/RedisTaggedCache.php

@@ -129,16 +129,11 @@ public function flush()
         $cachePrefix = $redisPrefix.$this->store->getPrefix();
 
         $cacheTags = [];
-        $keysToBeDeleted = [];
 
         foreach ($this->tags->getNames() as $name) {
             $cacheTags[] = $cachePrefix.$this->tags->tagId($name);
         }
 
-        foreach ($this->tags->entries() as $entry) {
-            $keysToBeDeleted[] = $this->store->getPrefix().$entry;
-        }
-
         $script = <<<'LUA'
             local prefix = table.remove(ARGV, 1)
 
@@ -152,12 +147,18 @@ public function flush()
             end
         LUA;
 
-        $connection->eval(
-            $script,
-            count($keysToBeDeleted),
-            ...$keysToBeDeleted,
-            ...[$cachePrefix, ...$cacheTags]
-        );
+        $entries = $this->tags->entries()
+            ->map(fn (string $key) => $this->store->getPrefix().$key)
+            ->chunk(1000);
+
+        foreach ($entries as $keysToBeDeleted) {
+            $connection->eval(
+                $script,
+                count($keysToBeDeleted),
+                ...$keysToBeDeleted,
+                ...[$cachePrefix, ...$cacheTags]
+            );
+        }
 
         $this->event(new CacheFlushed($this->getName()));
 

tests/Integration/Cache/RedisStoreTest.php

@@ -267,4 +267,28 @@ public function testIncrementWithSerializationEnabled()
         $store->increment('foo');
         $this->assertEquals(2, $store->get('foo'));
     }
+
+    public function testTagsCanBeFlushedWithLargeNumberOfKeys()
+    {
+        Cache::store('redis')->clear();
+
+        $tags = ['large-test-'.time()];
+
+        for ($i = 1; $i <= 5000; $i++) {
+            Cache::store('redis')->tags($tags)->put("key:{$i}", "value:{$i}", 300);
+        }
+
+        $this->assertEquals('value:1', Cache::store('redis')->tags($tags)->get('key:1'));
+        $this->assertEquals('value:2500', Cache::store('redis')->tags($tags)->get('key:2500'));
+        $this->assertEquals('value:5000', Cache::store('redis')->tags($tags)->get('key:5000'));
+
+        Cache::store('redis')->tags($tags)->flush();
+
+        $this->assertNull(Cache::store('redis')->tags($tags)->get('key:1'));
+        $this->assertNull(Cache::store('redis')->tags($tags)->get('key:2500'));
+        $this->assertNull(Cache::store('redis')->tags($tags)->get('key:5000'));
+
+        $keyCount = Cache::store('redis')->connection()->keys('*');
+        $this->assertCount(0, $keyCount);
+    }
 }